Serratula tinctoria
Saw-wort
Setaria viridis
Green Bristle-grass
Sherardia arvensis
Field Madder
Sibthorpia europaea
Cornish Moneywort
Silaum silaus
Pepper-saxifrage
Silene latifolia
White Campion
Silene uniflora
Sea Campion
Sisyrinchium montanum
American Blue-eyed-grass
Smyrnium olusatrum
Alexanders
Solanum dulcamara
Bittersweet
Solanum nigrum
Black Nightshade
Solidago virgaurea
Goldenrod
Sonchus asper
Prickly Sow-thistle
Sorbus aria
Common Whitebeam
Sorbus aucuparia
Rowan
Sorbus minima
Least Whitebeam
Sorbus stenophylla
Llanthony Whitebeam
Sorbus torminalis
Wild Service-tree
Sparganium angustifolium
Floating Bur-reed
Sparganium erectum
Branched Bur-reed
Sparganium natans
Least Bur-reed
Spergula arvensis
Corn Spurrey
Spergularia rubra
Sand Spurrey
Spiraea x rosalba
Intermediate Bridewort